Geology 101
Spring 2001
Exam #4

Part 1. Short Answer - Write the answers to these questions in the space provided.

1. Every introductory geology book talks about the Ogallala Aquifer. Why? Where is the Ogallala Aquifer, and what's going on with it? What's the problem, what caused the problem, and what is the solution?

2. What factors promote frequent flooding of the broad areas along the Red River of the North?

3. Dexy says that real caves only form in limestone, not in other types of rock. Is he out to lunch, or is he correct? Why does he say this?

4. What makes a glacier flow? Compare this with what makes a glacier retreat?

Part 2. True - False - Mark "T" or "F" on the answer sheet.

1. Coal typically occurs in layers of strata surrounded by layers of detrital sedimentary rocks.

2. Most forecasters think that we have so much petroleum left in the ground that we need not worry about running out.

3. Almost all the commercial reactors (that produce electricity) in the U.S. are fusion reactors, not fission reactors.

4. The term "groundwater recharge" refers to the rate at which groundwater is emitted by an artesian spring.

5. Wetlands are important because they may serve as collecting areas that replenish groundwater aquifers.

6. Groundwater sometimes flows upward against gravity.

7. To be an excellent aquifer, a rock must have both high permeability and high porosity.

8. An artesian aquifer is an unconfined aquifer in which the area of recharge lies at a lower elevation than the area of discharge

9. Stream slope (gradient) decreases as a stream approaches its mouth, but stream velocity generally increases.

10. Drawdown refers to pumping water from a well that is drilled into an confined aquifer.

11. Streams carry water from a watershed that is separated from other watersheds by a drainage basin.

12. In a meandering section of a stream, the fastest water is near the inside of the curves.

13. The two principle types of glaciers are alpine glaciers and valley glaciers.

14. Glacial ice forms when snow is transformed. Firn is an intermediate form between snow and glacial ice.

15. Very young (juvenile) streams are more likely to meander than older streams.

16. When glaciers retreat, it is because the ice is pulled back uphill.

17. Milankovitch cycles help explain continental glaciation as depending on variations in the amount of solar energy reaching the Earth.

18. A 10-year flood is a flood that has a 1 in 10 chance of occurring every year.

19. The term "karst" refers to caves or landform features associated with caves

20. Horns, aretes and tarns are landforms created by flowing water.

21. In a braided stream there is little net erosion or deposition.

22. Alluvial fans form when a stream enters an ocean or a lake.

23. The Red River (our Red River) flows into the Mississippi River.

24. A stream's suspended load includes stuff dissolved in the water.

25. In general, urbanization causes an increase in flood size and frequency.

Part 3. Multiple Choice - Mark correct answer on the answer sheet.

1. North Dakota coal is

a. a metamorphic rock

b. a layer in a pile of igneous rock

c. mostly lignite

d. very high grade coal

e. exported to California and other states for burning

2. The desalinization of seawater is an uncommon way to relieve water shortages even in areas near the ocean because:

a. it is usually not economically feasible

b. sufficient quantities of water cannot be produced

c. desalinization technology is still in its infant cycles

d. it would upset the global hydrologic cycle

e. all of the above

3. A round bowl shaped valley at a glacier's head is a __________.

a. cirque

b. moraine

c. flood plain

d. arete

e. kettle lake

4. A type of glacial deposit, composed primarily of till is a ____________.

a. cirque

b. moraine

c. flood plain

d. arete

e. kettle lake

5. Stream piracy occurs when:

a. erosion causes a waterfall to migrate upstream and reduce its height until it no longer exists.

b. a stream cuts through a separating strip and bypasses a stream meander.

c. one stream captures the headwaters of another stream on the opposite side of a drainage divide.

d. degradation causes the stream to erode its bed and reduce its gradient.

e. artificial levees are built

6. The primary difference between stalactites and stalagmites is that:

a. stalactites are made of calcite but stalagmites are made of dolomite

b. stalactites are composed of travertine, but stalagmites are made of calcium carbonate

c. stalactites form from water entering the roof of a cave, whereas stalagmites form from water entering the floor of a cave

d. stalactites are depositional features, but stalagmites are erosional remnants

e. stalactites hang suspended from a cave rood, whereas stalagmites protrude upward from the cave floor

7. Petroleum originates from the accumulation and decomposition of

a. marine organisms

b. swamp vegetation

c. animals such as dinosaurs

d. marine shellfish

e. any of the above

8. Coal originates from the accumulation and decomposition of

a. bananas

b. marine organisms

c. swamp vegetation

d. animals such as dinosaurs

e. marine shellfish

9. Which creates a lower base level for rivers and streams?

a. sea level falls or land rises

b. sea level rises or land rises

c. rain increases

d. sea level drops or land subsides

e. sea level rises or land subsides

10. Erosion by moving glaciers can produce

a. rock flour

b. glacial striations

c. rounded hills

d. plucking

e. all of the above

11. The largest particle a stream can move is the stream's _____________.

a. capacity

b. limit

c. competence

d. velocity

e. load

12. Where is erosion concentrated along a meandering stream?

a. on the straight parts of the channel

b. on the outer parts of the meander loops

c. on the inner parts of the meander loops

d. on the river's bottom

e. in flood plain

13. During the Pleistocene, the amount of ice in the Northern Hemisphere was about twice the amount in the Southern Hemisphere. Why?

a. Southern hemisphere ice had a hard time crossing the Antarctic Oceans

b. It was warmer in the southern hemisphere

c. There is more gravity in the southern hemisphere

d. The Pleistocene was only 25 million years ago

e. The Earth is tilted so different amounts of solar radiation reach the southern polar regions and the northern polar regions.

14. Oil traps:

a. must include a good reservoir rock

b. must include a good cap rock

c. can stop upward migration of oil

d. can stop upward migration of gas

e. all of the above are correct

15. Which of the following are true about the Holocene and Pleistocene?

a. they are both names for Epochs

b. they are both part of the Quaternary period

c. Holocene time is more recent than Pleistocene

d. The Pleistocene was a time of widespread continental glaciation, the Holocene was not.

e. All of the above

16. Most of the world's fresh water is

a. in the oceans

b. in lakes and streams

c. in ice and snow

d. groundwater

e. in artificial reservoirs created by dams

17. When it rains on land, the result may be

a. runoff

b. infiltration

c. evaporation

d. erosion

e. all of the above

18. Most of the water that people use goes for

a. driving cars

b. industrial uses

c. washing and other things related to sanitation

d. agriculture, especially irrigation

e. drinking

19. Which of the following are reasons that the nuclear energy industry is not doing too well?

a. nuclear energy is expensive compared to other energy sources

b. people are concerned about a serious accident

c. we know of no good way to get rid of nuclear waste

d. no one wants a nuclear plant in their backyard

e. all of the above

20. Which of the following is true about lignite?

a. it burns well compared with other coals

b. it is a type of petroleum

c. it is the only type or coal not formed from organic debris

d. it often produces sulfur, carbon dioxide and particulates when burned

e. all of the above

21. The thing that makes Greenhouse gases warm the earth is that

a. they emit heat

b. they emit radiation

c. they conduct heat

d. they let sunlight in but don't let heat out

e. the blanket the earth and stop atmospheric circulation from moving heat to the stratosphere

22. Most major caves form in

a. limestone

b. shale

c. granite

d. basalt

e. quartz

23. A curved lake produced when a stream cuts off a meander

a. oxbow

b. incised meander

c. meander scar

d. point bar

e. pothole

24. ____________ are dripstone features found in caves

a. karsts

b. sinkholes

c. speleothems

d. sinks

e. aquitards

25. When ice breaks off a glacier to become an iceberg, the process is called ____________.

a. ablation

b. calving

c. wasting

d. erosion

e. plucking